With the rising costs and environmental concerns associated with fossil fuels, renewable energy sources have become increasingly important. The development of renewable fuel sources provides a means for reducing the dependence on fossil fuels. Accordingly, many different areas of renewable fuel research are currently being explored and developed.
With its low cost and wide availability, biomass has increasingly been emphasized as an ideal feedstock in renewable fuel research. Consequently, many different conversion processes have been developed that use biomass as a feedstock to produce useful biofuels and specialty chemicals. One of the useful products that may be derived from biomass is a liquid product commonly referred to as “bio-oil.”
Bio-oil may be processed into transportation fuels, hydrocarbon chemicals, and specialty chemicals. However, most bio-oils that are produced contain high amounts of organic acids such as carboxylic acids. Due to this high acid content, bio-oils can cause corrosion or fouling of conventional refinery equipment. Thus, a bio-oil's high acid content thereby inhibits its ability to be processed, stored, and refined in conventional refineries. In an attempt to remedy this problem, many bio-oils have been subjected to various upgrading processes in order to lower their acid content. Although these treated bio-oils may contain lower amounts of acid, such upgrading processes are not cost-effective and can decrease the overall bio-oil yield.
Accordingly, there is a need for an improved process for upgrading a bio-oil that effectively removes undesirable acidic components from the bio-oil, but does not negatively impact bio-oil yield at the same time.